RAS for Peer to Peer Win 98/2000/XP

I have two computers in a remote location. One machine is running WIN 2000 the other XP. My central point is running WIN 98/2000. I need to be able to login and get files from the WIn 2000 and XP machines frequently without the user having to do anything. Both machines are connected to a rtelephone line I can dail from my WIN 98/2000 machine in the central office. I would like to know how do configure the Central and also the remote machines.